High Temps 2011 Yukon XL Denali

[gooffeyguy]

Do the fans on these trucks still run when at highway speeds? I know many cars don't, only when below a certain speed

2001 Yukon SLT
2012 Yukon Denali XL
2011 Yukon Denali RIP 5/20/18

 

[Doubeleive]

Do the fans on these trucks still run when at highway speeds? I know many cars don't, only when below a certain speed

2001 Yukon SLT
2012 Yukon Denali XL
2011 Yukon Denali RIP 5/20/18

don't know, never watched the tech2 data for that

 

[BG1988]

don't know, never watched the tech2 data for that

if it's running hot run the heater with the windows open that is a old trick in the book to do when it's overheating

 

[Foggy]

The fans do run at any speed IF commanded by the PCM at the temps that
are preprogrammed.
You could/should do something about 235 temps while moving at speed.
New or upgraded radiator. Trans cooler or Trans Pan (deeper)
Better fans if yours dont have them. Make sure your coolant
is correct. In kalifornia, I'd think a 60%-70% water to dexcool would be good and
use an additive like lubegard or redline for coolant.
Also, you could go with a 180* Tstat and program your fans to come on earlier with
a handheld programmer like a diablosport or similar
Water Pump is also an easy replace if yours is original, might not be as efficient too

 

[BrainDead]

The 235 is the engine coolant. I tow a trailer to San Diego that weighs about 6000-7000 lbs and my Denali hits 235 on freeway with slightest uphill grade. I’ve read on this forum that the engine runs hot and that is normal but it always freaks me out . I’m not sure what the Denali weighs fully loaded. I will eventually buy a diesel to tow but have to keep using the Denali in mean time.

I’m trying to keep the wear and tear down on engine and I figured extended trips towing and running engine at 235 would not be good.

Also, I don’t remember exact trans temp but it was definitely closer to 230-240 on the hills. I was thinking if I lowered the trans temp my engine coolant would run cooler as well. Am I way off?

I’ll review that thread you linked as well. Thanks!!

If you're overheating at hwy speeds on semi flat terrain, a lower thermostat and heavy duty cooling fans ain't gonna do much, show me how an electric fan can pull more air through the radiator than doing 65mph on the fwy...

You've obviously have other issues going on and I'm guessing it's a clogged radiator, been there with my 02 2500 Sierra with a 6.0L

Can you post up some vehicle info i.e. year, mileage, maintanence records on cooling system

 

[avalonandl]

Yeah flush the radiator and also check for debris in the cooling fins blocking air flow.

The water pump maybe failing too....very common

 

[petethepug]

Good thing your on top of this. The radiator fins can be clogged on you’d never know it until it’s removed and held up to the sun.

The underhood temps in these trucks can get out of control because of heat soak. You’d due well to look for an oem style, all metal radiator with an extra row. It’d help out two fold. You’d have insurance against failures known to occur from the plastic tanks cracking due on high load and know it’s operating at 110% efficiency.

Increase the size of the trans cooler and relocate it away from the radiator/ condenser area. You’d stop the heat of the trans cooler from being passed into the a/c & coolant system. That adds to the trans cooling capacity and keeps the trans cooler heat exchange out of the system load.

Adding a water wetter to the radiator fluid upon flush out would really add an unmatched layer of protection and keep the pressures within tolerance to stave off hose and fitting damage.


Sent from my iPhone using Tapatalk

 

[rjr]

Do not overlook what swathdiver said above: switch to 60% water/40% antifrreze. While that lowers the boiling temp, it also raises the specific heat of the coolant mix and it can remove more BTUs of heat from the engine, causing it to run cooler. Learned this years ago from running tests on my twin engine cabin cruiser, after a chemist friend alerted me to the the specific heat issue.

 

[Foggy]

Just to add: Water cools/ dissipates heat better than antifreeze.
But of course you need some amount of antifreeze for is lubrication and anti
corrosion properties.
In my summer fun vehicles I run only about 20% antifreeze with 80% distilled
water and an additive like lubegard/water wetter/ etc

The specific problem in this case is probably a gooped up radiator - inside AND Outside
And maybe an old mixture of coolant

 

[Monz11]

mine came with the dual 500w 5 blade fans, and the oem trans cooler was a little itty bitty thing
kirk you can check you glove box for the list of codes and see if one of them say's K5L (heavy duty cooling package) , if it's not listed then you can upgrade the oem cooling fans to the dual 700w used ones are generally about $125 (they are plug-n-play) and you can add a true-cool 40k transmission cooler fairly easily as well those also run about $125 (new) I do not tow anything regularly but I do drive it pretty hard here in central California and with the true-cool and a B&M deep transmission pad my trans temps dipped from 220 way down to 165 usually it's less depending on the season 120-135, I can make it get to 180 if I try really really hard but it's hasn't gone past that since. Engine has never budged except once up at about 8000 feet it went up to maybe 230 because I was pushing it 90+ on big upgrades and it was 70deg's out in the summer at that elevation, even then the trans temp stayed at 165.

I pulled the trigger on a Mishimoto radiator, B&M deep tranny pan and ended up with the derale tranny cooler. My Hoe has the puny dual 5 blade fans, but I do have the K5L code, any advice on aftremarket cooling fans? Or are these OEM ones 700W? I was going to take your suggestion on the 7/9 esky fans, but not an electrical geek?
Thanks